I came across this while searching for SCCA AutoX,
I used to do this at Fort Mead, 20 to 30 years ago, In the National Security Agency (NSA) parking lot. in a Dodge Colt Turbo, (small like a Mini, with alot of power for the small car.

I wanted to find out about local SCCA in the Triangle Area,
It changed a bit. what I found is the different classes and the AutoX
in addition to the Rally and it various forms,http://www.thscc.com/index.php/rally.../what-is-rally
I thought I'd share my findings
so there is Rally and RallyX. to do the off road (dirt/gravel) (not the 4x4 Bogger mud stuff).
probably the all wheel drive Subaru, and possible the R60 All4 or any off road style like car.
I found it interesting, but I don't want to tear up my ride.
Just wanted to see if any one has done this, and possible share there experiences.

I have a few friends that participate in RallyX over there in the east. It's definitely not something I would personally do in a new car or daily driver. It definitely takes a toll on the car and a lot of the cars that show up are "beaters" for a reason.

There aren't gnarly jumps or mud bogging as you say, but even putting your car through uneven gravel at speed will take a toll on the suspension and the inevitable rock chips are a bit harder to bear on a new vehicle.

With that said, if you were up for the wear and tear, it would be a blast in an R60 or new subaru.